In adults, the carapace and plastron are a rich, dark brown except for the distinct creamy-yellow stripe down the vertebral keel, and the lightly pigmented lower edges of the marginal scutes and adjacent plastral scutes that effectively form a creamy-yellow rim around the edge of the plastron. In addition to the prominent vertebral keel, two broken lateral keels (one on each side) may be evident along the pleural scutes. The carapace is joined to the plastron by ligaments and not the bony bridge found in most other turtles. Because the plastron has a hinge between the pectoral and abdominal scutes the flexibility endowed by the ligaments allows these turtles to close up very tightly.

The skin of the limbs is brown. The top of the head is a pale green marked on each side by a striking bright yellow line that goes from behind the eye to the back of the head. The skin of the chin and neck is colored a delicate apricot to pink or yellow. There are five claws on the forefeet and four on the rear. Sexing these turtles is not easy. Mature males have broader and larger tails than do females; the tails may be so broad in males that they appear to be triangular in shape.